首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   838篇
  免费   56篇
  国内免费   47篇
耳鼻咽喉   3篇
儿科学   52篇
妇产科学   28篇
基础医学   105篇
口腔科学   40篇
临床医学   103篇
内科学   195篇
皮肤病学   10篇
神经病学   80篇
特种医学   118篇
外科学   54篇
综合类   12篇
预防医学   48篇
眼科学   8篇
药学   53篇
  1篇
肿瘤学   31篇
  2023年   5篇
  2022年   5篇
  2021年   7篇
  2019年   8篇
  2018年   16篇
  2017年   12篇
  2016年   17篇
  2015年   17篇
  2014年   28篇
  2013年   40篇
  2012年   21篇
  2011年   20篇
  2010年   23篇
  2009年   24篇
  2008年   15篇
  2007年   54篇
  2006年   30篇
  2005年   28篇
  2004年   13篇
  2003年   7篇
  2002年   15篇
  2001年   8篇
  2000年   8篇
  1999年   18篇
  1998年   45篇
  1997年   54篇
  1996年   55篇
  1995年   45篇
  1994年   31篇
  1993年   31篇
  1992年   17篇
  1991年   18篇
  1990年   13篇
  1989年   20篇
  1988年   30篇
  1987年   21篇
  1986年   17篇
  1985年   17篇
  1984年   8篇
  1983年   10篇
  1982年   11篇
  1981年   9篇
  1980年   12篇
  1979年   3篇
  1978年   8篇
  1977年   11篇
  1976年   3篇
  1975年   5篇
  1973年   2篇
  1960年   1篇
排序方式: 共有941条查询结果,搜索用时 15 毫秒
931.
In these case reports, we investigated pandemic influenza 2009 vaccination of primary hypogammaglobulinaemic patients. Three combined variable immunodeficiency (CVID) patients and one X-linked agammaglobulinaemia (XLA) patient were vaccinated with the pandemic vaccine A/California/7/2009 (H1N1)-like split virus (X179a) adjuvanted with the oil-in-water emulsion AS03. Subsequently, serum and peripheral blood mononuclear cells were sampled and used to measure the haemagglutination inhibition (HI) and antibody-secreting cell (ASC) responses. In addition, the IFN-γ, IL-2 and TNF-α producing CD4(+) Th1-cell response was determined as these cytokines are important indicators of cell-mediated immunity. Two of the CVID patients responded to vaccination as determined by a >4-fold rise in HI antibodies. These subjects also had influenza-specific ASC numbers, which, albeit low, were higher than prevaccination levels. In addition, vaccination induced CD4(+) Th1-cell responses in both the XLA patient and the CVID patients, although the frequency of influenza-responsive cells varied amongst the patients. These results suggest that hypogammaglobulinaemia patients can mount a CD4(+) Th1 cell-mediated response to influenza vaccination and, additionally, that influenza vaccination of some hypogammaglobulinaemia patients can produce an influenza-specific humoral immune response. The findings should be confirmed in larger clinical studies.  相似文献   
932.
933.
BackgroundTo evaluate characteristics and mortality related to post-stroke fatigue (PSF).MethodsAll surviving stroke patients admitted to the Stroke Unit, Haukeland University Hospital, between February 2006 and November 2008 were sent a postal questionnaire including the Fatigue Severity Scale (FSS), the hospital anxiety and depression scale (HADSD), and the Barthel Index (BI) at least 6 months after stroke onset. Survival among patients returning the questionnaire was determined by November 2009. PSF was defined as FSS score  5.ResultsAmong 377 patients returning the questionnaire, 42.3% had PSF. Logistic regression showed that PSF was independently associated with pre-stroke depression, leucoaraiosis, myocardial infarction, diabetes mellitus, pain, and sleeping disturbances. Mean FSS score was lower among TIA patients than among patients with minor cerebral infarction (patients with BI = 100) (P = .002). Cox regression analysis showed mortality to be associated with PSF.ConclusionThere is a multifactorial basis for PSF suggesting different therapy options. Cerebral lesions may cause PSF in some patients. Post-stroke fatigue is associated with higher mortality.  相似文献   
934.
We report a population-based investigation on adult acute precursor B lymphoblastic leukemia, Burkitt's lymphoma and T lymphoblastic lymphoma in a defined geographic area. The age-adjusted incidence rates for the three diagnostic groups were 0.47, 0.16 and 0.2 per 100,000 per year, respectively. Clinical characteristics and outcome following treatment are reported.  相似文献   
935.
目的:观察普伐他汀、阿司匹林联用对家兔颈动脉血管成形术后内膜增殖进展的影响及其作用机制。方法:实验于2002-03/12在北京中医药大学教育部中医内科学重点学科实验室完成。雄性日本大耳白兔30只,体质量1.8~2.0kg,动物适应性喂养1周后随机数字表法分为正常对照组(n=9)、假手术组(n=6)、模型组(n=9)、治疗组(n=6)。模型组和治疗组动物氯胺酮、速眠新混合肌注麻醉,沿气管正中切开皮肤,剥离颈总动脉,给予电刺激。术后第2天开始饲喂高脂饲料(胆固醇:0.7%,猪油:3%,普通饲料96.3%);正常对照组无任何干预措施;假手术组仅剥离颈总动脉,不做电刺激,喂高脂饲料;动物连续喂养8周后超声评价颈总动脉,根据B超选择颈总动脉有斑块或血流明显改变者作颈总动脉球囊扩张术。正常对照组、模型组、假手术组喂普通饲料,治疗组喂普伐他汀与阿司匹林含药饲料(普伐他汀5.046mg/kg,阿司匹林2.268g/kg),4周后测血脂和C-反应蛋白浓度、血清一氧化氮及转化生长因子β水平,观察颈动脉组织病理形态学改变,半定量分析增生内膜中胶原含量的变化,免疫组织化学方法分析增生内膜中巨噬细胞和平滑肌细胞阳性百分率。结果:纳入大耳白兔30只,正常对照组中途死亡1只,死因为牙齿畸型影响进食;模型组1只因电刺激8周时超声评价颈动脉未形成斑块及血流无明显改变而剔出实验,进入分析28只。与模型组比,普伐他汀与阿司匹林联用4周后,治疗组胆固醇及三酰甘油水平明显下降[(4.12±2.30),(0.74±0.17)mmol/L;(0.47±0.27),(0.39±0.14)mmol/L;P<0.05],血清C-反应蛋白水平和转化生长因子β水平均降低[(0.86±0.27),(0.57±0.30)mg/L;(3.45±0.77),(3.23±0.34)ng/L;P<0.05],一氧化氮水平升高[(41.79±35.78),(90.14±32.54)mmol/L;P<0.05],动脉内膜增殖程度明显减轻,管腔狭窄率降低,内中膜厚度及内中膜面积比降低[(71.91±14.90)%,(47.20±18.74)%;(0.41±0.17),(0.26±0.04)mm;1.66±0.63,0.78±0.34;P均<0.05],动脉内膜胶原含量减少(30.92±10.05,21.93±5.81,P<0.01),动脉内膜巨噬细胞阳性百分率降低[(13.94±4.91)%,(7.29±7.28)%,P<0.05],平滑肌细胞含量无明显差异(38.37±5.67,35.79±10.68,P>0.05)。结论:普伐他汀与阿司匹林联用具有抑制内膜增生和减少新生内膜胶原含量的作用,其机制与两药抑制炎症反应、保护内皮功能及抑制细胞外基质生成等有关。  相似文献   
936.
目的:利用巢式逆转录-聚合酶链反应扩增的方法,从肌肉组织中扩增人骨形成蛋白2全长cDNA并构建真核表达载体系统。方法:实验于2003-10/2005-10在苏州大学基因工程教研室和北京大学第三医院骨科实验室完成。提取成人肌肉组织内的总RNA,设计内外两对引物以巢式逆转录-聚合酶链反应扩增方法分两次扩增出人骨形成蛋白2全长1188bp基因,经T-A克隆装入pUCM-T质粒载体内,测序验证后,将克隆质粒以Hind Ⅲ和Xba Ⅰ双酶切后与pcDNA3.0载体相连接,构建真核表达载体系统。结果:利用巢式逆转录-聚合酶链反应扩增方法能从成人肌肉组织内扩增出1188bp的人骨形成蛋白2全长cDNA基因,其测序结果显示与Genebank报道序列完全相符。将扩增序列双酶切后与pcDNA3.0载体相连接,经电泳验证,能构建人骨形成蛋白2全长基因的真核表达系统。结论:巢式逆转录-聚合酶链反应扩增方法能从成人肌肉组织内扩增出人骨形成蛋白2全长cDNA基因,并克隆构建真核表达载体系统,为下一步基因组织工程人工骨实验奠定基础。  相似文献   
937.
李兰敏  徐世平 《药学学报》1995,30(7):556-560
Since compounds Ⅲ and Ⅳ possess retinoid-like action and analogues of Ⅰ inhibit some cancer cells ,seventeen derivatives of chlorophenoxy acetamide were synthesized.Of the seven compounds screened ,two exhibit cytostatic activity(1 and 2).Mass spectra showeda special expulsion of SO2 and CO from the sulfonamide compounds,Nuclear magnetic resonancesplitting patterns of these compounds also showed interesting features.  相似文献   
938.
何录梅  周毅  刘小辉 《医学争鸣》2005,26(7):669-669
1病理报告女,45岁,医务工作者.2003-10入我院肿瘤科.自述6 mo前无明显诱因,出现下腹部隐痛,呈进行性加重,疼痛与体位变化无关,但咳嗽、活动时加重,并向腰、骶部放射,伴有乏力、全身不适.无意中自己在腹部触膜到一5 cm×5 cm大小的包块,故要求住院进一步确诊.患病后食纳尚可,二便正常,质量无变化.  相似文献   
939.
正The leading form of dementia worldwide, Alzheimer 's disease(AD) is a common neurodegenerative disorder.The underlying causes of AD are not well understood, and no current treatments are preventing the onset or delay progression of the disease.Currently, most investigation is directed towards the amyloid-beta(Aβ) and tau pathologies,  相似文献   
940.
Racial concordance has been identified as a potential strategy to improve the perinatal health of Black women and birthing people by mitigating implicit bias and improving mutual trust, healthy communication, and satisfaction. In a recent article published in BIRTH: Issues in Perinatal Care, Bogdan-Lovis et al. surveyed 200 Black women to determine whether they possessed a race and gender practitioner preference for their birth practitioner and examined whether race and gender concordance was associated with greater birth satisfaction and perceived respect, trust, practitioner competence, empathy, and use of inclusive communication. In this commentary, written by a group of Black midwives, we respond to the study and offer a vision for race-concordant care that encompasses cultural safety provided in a community-based setting.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号